An integrated overflow pressure regulating valve for an ignition-type direct injection heavy oil engine air pump

Abstract

This invention relates to the field of engines, specifically disclosing an integrated overflow pressure regulating valve for a spark-ignition direct injection heavy oil engine. The valve includes: a housing; an oil chamber, an air chamber, and a compressed air chamber located within the housing; an oil return passage; a pressure relief passage; a flexible valve plate; a gas check valve; an air pump piston; and a pressure relief valve connected to the pressure relief passage. This invention integrates the compressed air chamber, air chamber, and oil chamber into a compact structure. It utilizes the heat generated by compressed air to directly preheat the heavy oil in the oil chamber, and the absorption of heat by the heavy oil also facilitates heat dissipation of the working parts within the compressed air chamber. By limiting the critical value of the flexible valve plate's deformation force, the pressure relief valve's through pressure value, and the design of the gas check valve, it not only achieves precise independent pressure regulation of the oil and air pressures but also ensures the stability of the back pressure value.

Description

Technical Field

[0001] This invention belongs to the field of engine technology, and specifically relates to an integrated overflow pressure regulating valve for an ignition-type direct injection heavy oil engine. Background Technology

[0002] Spark-ignition direct injection engines are widely used in aero-engines. Due to the high viscosity, high flash point, and low volatility of heavy fuel oil, it is safer and more reliable during transportation and storage, making it highly favored in military, marine, and aero-engine fields, especially in the development of small unmanned aerial vehicle (UAV) engines. However, the properties of heavy fuel oil are a double-edged sword; while its stability is good, its ignition performance is significantly affected. To solve this problem, heating the heavy fuel oil and using auxiliary gas to atomize it into extremely fine particles are commonly used to improve its ignition performance. Typically, an air compressor provides compressed air, and an overflow valve controls the direct pressure difference between oil and air. However, when applied to aero-engines using heavy fuel oil, the overflow valve and air compressor must simultaneously meet the following conditions:

[0003] 1. Ensure the stability of the back pressure between air pressure and oil pressure.

[0004] 2. Ensure continuous heating and temperature rise of the heavy oil.

[0005] 3. Compact structure, lightweight, and easy to maintain. Summary of the Invention

[0006] The purpose of this invention is to provide an integrated overflow pressure regulating valve for an ignition-type direct injection heavy oil engine, thereby overcoming the shortcomings of existing technologies, such as the inability to achieve stable back pressure control between air pressure and oil pressure, the inability to continuously heat heavy oil, and the non-compact and heavy structure.

[0007] To achieve the above objectives, the present invention provides an integrated overflow pressure regulating valve for an ignition-type direct injection heavy oil engine, comprising: an oil chamber having a back pressure oil port; an air chamber having a back pressure air port and an air chamber inlet, the back pressure air port being connected to the back pressure oil port, and the air chamber being connected to a pressure relief passage; a return oil passage located on one side of the oil chamber, one end of the return oil passage having a return oil port connected to the back pressure air port; a flexible valve plate sealing the back pressure oil port and the return oil port on one side, and sealing the back pressure air port on the other side; a compression air chamber having an outlet connected to the air chamber inlet, and a one-way gas valve being provided between the outlet and the air chamber inlet; an air pump piston located within the compression air chamber and capable of compressing the air within the compression air chamber; a pressure relief valve connected to the pressure relief passage; and a housing, wherein the oil chamber, the air chamber, and the compression air chamber are all located within the housing.

[0008] Preferably, the above technical solution further includes a pneumatic valve seat disposed in the air chamber, the pneumatic valve seat having a plurality of pneumatic valve holes, and a first spring disposed on the pneumatic valve seat, the first spring pressing the valve core against the other side of the flexible valve plate.

[0009] Preferably, in the above technical solution, the oil cavity is also connected to the oil outlet and the oil inlet.

[0010] Preferably, in the above technical solution, the air cavity is also connected to the air outlet.

[0011] Preferably, in the above technical solution, the compressed air chamber is further provided with an air inlet.

[0012] Preferably, in the above technical solution, the air outlet is connected to the air inlet of the air chamber, and an annular limiting surface is provided between the air outlet and the air inlet of the air chamber, and an annular oil groove is provided on the annular limiting surface surrounding the air outlet.

[0013] Preferably, in the above technical solution, the gas one-way valve includes: a valve plate, which is slidably disposed in the gas chamber, and the diameter of the valve plate is adapted to the diameter of the gas inlet of the gas chamber; and a second spring, which is disposed on one side of the valve plate, so that the valve plate is tightly attached to the annular limiting surface.

[0014] Preferably, in the above technical solution, the pressure relief valve includes: a valve cavity disposed in the housing, one end of which is connected to the pressure relief passage, and the other end of which is connected to the vent; a pressure relief valve seat disposed at one end of the valve cavity, the pressure relief valve seat having a pressure relief valve hole; a valve core slidably disposed in the valve cavity, one end of which contacts the pressure relief valve seat via a steel ball and is capable of sealing the pressure relief valve hole; and a third spring disposed between the valve core and the other end of the valve cavity.

[0015] Compared with existing technologies, the present invention has the following advantages:

[0016] 1. This invention not only provides a stable pressure value for both air pressure and oil pressure separately, but also ensures the stability of the back pressure between air pressure and oil pressure.

[0017] 2. This invention integrates the compressed air chamber and the oil chamber into one compact structure. It can also transfer the heat generated during gas compression to the heavy oil in the oil chamber, which not only provides heat dissipation protection for the compressed air components, but also heats the heavy oil and improves its ignition performance. Attached Figure Description

[0018] Figure 1 This is a structural diagram of the integrated overflow pressure regulating valve for the air pump of the ignition-type in-cylinder direct injection heavy oil engine of the present invention.

[0019] Figure 2 yes Figure 1 A partial magnification of the pressure relief valve in the middle. Figure I .

[0020] Explanation of key figure labels:

[0021] 1-Oil chamber, 2-Air chamber, 3-Flexible valve plate, 4-Compressed air chamber, 5-Air pump piston, 6-Housing shell, 7-Valve core, 8-Valve plate, 9-Valve chamber, 10-Connecting rod, 101-Piston pin, 11-Back pressure oil port, 12-Outlet oil passage, 13-Inlet oil passage, 14-Return oil passage, 15-Return oil port, 21-Back pressure air port, 22-Air chamber inlet, 23-Pressure relief air passage, 24-Outlet air passage, 25-Air pressure valve seat, 26-Air pressure valve hole, 41-Outlet air, 42-Inlet air, 43-Annular limiting surface, 44-Annular oil groove, 71-First spring, 81-Second spring, 91-Pressure relief valve seat, 92-Valve hole, 93-Valve core, 94-Steel ball, 95-Third spring, 96-Relief port, 97-Air pump crankcase. Detailed Implementation

[0022] The specific embodiments of the present invention will now be described in detail with reference to the accompanying drawings, but it should be understood that the scope of protection of the present invention is not limited to the specific embodiments.

[0023] like Figure 1 As shown, the integrated overflow pressure regulating valve of the ignition-type direct injection heavy oil engine air pump in this embodiment includes: an oil chamber 1, an air chamber 2, a flexible valve plate 3, a compressed air chamber 4, an air pump piston 5, a housing 6, a valve core 7, a valve plate 8, a connecting rod 10, a piston pin 101, a back pressure oil port 11, an oil outlet 12, an oil inlet 13, a return oil channel 14, a return oil port 15, a back pressure air port 21, an air chamber inlet 22, a pressure relief air channel 23, an air outlet 24, a pressure valve seat 25, a pressure valve hole 26, an air outlet 41, an air inlet 42, an annular limiting surface 43, an annular oil groove 44, a first spring 71, a second spring 81, and an air pump crankcase 97. The housing 6 contains, from top to bottom, an oil chamber 1, an air chamber 2, a compressed air chamber 4, and an air pump crankcase 97. The top of the oil chamber 1 is connected to the oil inlet passage 13, which is connected to the oil pump. The side of the oil chamber 1 is connected to the air outlet passage 12, which is connected to the oil inlet of the injector. The bottom of the oil chamber 1 has multiple back pressure oil ports 11. The return oil passage 14 runs through the oil chamber 1 from top to bottom and is fixed in the middle of the oil chamber 1. The lower end of the return oil passage 14 is the return oil port 15. Multiple back pressure oil ports 11 surround the return oil port 15 in the middle. The end face of the return oil port 15 and the lower end face of the back pressure oil port 11 are on the same plane. The upper end of the return oil passage 14 extends to the outside of the oil chamber 1 and is connected to the oil tank.

[0024] A back pressure air port 21 is opened above the air chamber 2, which is directly opposite to the back pressure oil port 11 and the return oil port 15. The back pressure oil port 11 and the return oil port 15 can fall entirely or partially within the area of ​​the back pressure air port 21, thereby connecting the oil chamber 1, the return oil passage 14 and the air chamber 2. A flexible valve plate 3 is installed between the back pressure air port 21 and the back pressure oil port 11 and the return oil port 15. The circumference of the flexible valve plate 3 is fixed to the housing 6. The middle part of the flexible valve plate 3 can be slightly bent. The upper side of the flexible valve plate 3 covers the plane of the back pressure oil port 11 and the return oil port 15, which can seal the back pressure oil port 11 and the return oil port 15 at the same time. The lower side of the flexible valve plate 3 covers the back pressure air port 21, which can seal the back pressure air port 21. The bottom of the air chamber 2 is provided with an air chamber inlet 22. Inside the air chamber 2, near the air inlet 22, a pressure valve seat 25 is fixedly installed. The pressure valve seat 25 has multiple pressure valve holes 26. The valve core 7 is located at the back pressure port 21. A first spring 71 is installed between the valve core 7 and the pressure valve seat 25. The valve core 7 is pushed against the lower side of the flexible valve plate 3 by the first spring 71, so that the upper side of the flexible valve plate 3 can fit tightly with the oil return port 15. The top of the compressed air chamber 4 is an air outlet 41, and the diameter of the air outlet 41 is smaller than the diameter of the air inlet 22 of the air chamber. The air outlet 41 is connected to the air inlet 22 of the air chamber, so that the mating surface between the air outlet 41 and the air inlet 22 of the air chamber forms an annular limiting surface 43. An annular oil groove 44 is opened around the air outlet 41 on the annular limiting surface 43. The valve plate 8 is installed in the air chamber 2 in a way that allows it to slide up and down, and the outer diameter of the valve plate 8 is slightly smaller than the diameter of the air inlet 22 and larger than the outer diameter of the annular oil groove 44. The second spring 81 is installed between the valve plate 8 and the air pressure valve seat 25. The valve plate 8 and the second spring 81 together constitute a gas one-way valve. The housing 6 also has a pressure relief passage 23 and an air outlet passage 24 respectively. One end of the pressure relief passage 23 and the air outlet passage 24 are connected to the air chamber 2. The other end of the air outlet passage 24 is connected to the auxiliary air inlet in the fuel injector. The pressure relief passage 24 is connected to the air vent 96 through a pressure relief valve.

[0025] The bottom of the compressed air chamber 4 is connected to the crankcase 97 of the air pump. An air inlet 42 connected to the crankcase 97 of the air pump is opened on the side wall of the compressed air chamber 4. The air pump piston 5 is installed in the compressed air chamber 4 and can reciprocate along the direction of the air outlet 41. The connecting rod 10 is connected to the air pump piston 5 through the piston pin 101. The connecting rod 10 is located in the crankcase 97 of the air pump and connected to the crankshaft of the air pump. The vent 96 is connected to the crankcase 97 of the air pump.

[0026] Continue to refer to Figure 2The pressure relief valve in this embodiment includes: a valve cavity 9, a pressure relief valve seat 91, a valve hole 92, a valve core 93, a steel ball 94, and a third spring 95. A cylindrical valve cavity 9 is formed inside the housing 6. The upper end of the valve cavity 9 is connected to the pressure relief passage 23, and the lower end of the valve cavity 9 is connected to the vent 96. A pressure relief valve seat 91 is fixed at the upper end of the valve cavity 9, with a pressure relief valve hole 92 extending vertically through the center of the seat. The opening of the pressure relief valve hole 92 is aligned with the opening of the pressure relief passage 23. The valve core 93 is installed inside the valve cavity 9 and can slide up and down along the cavity. A steel ball 94 is located on the top of the valve core 93. A third spring 95 is installed between the valve core 93 and the bottom of the valve cavity 9. Under the action of the third spring 95, the valve core 93 can press the steel ball 94 against the pressure relief valve hole 92 and seal it.

[0027] Next, the working principle of the integrated overflow pressure regulating valve of the spark-ignition in-cylinder direct injection heavy oil engine air pump in this embodiment will be explained so that those skilled in the art can better understand the technical solution of this embodiment.

[0028] 1. Integrated Structure and Heavy Oil Preheating Principle: The oil chamber 1, air chamber 2, compressed air chamber 4, and air pump crankcase 97 are all integrated in the same housing 6; the flexible valve plate 3 isolates the oil chamber 1 and air chamber 2 from each other, and the valve plate 8 in the gas one-way valve isolates the air chamber 2 from the compressed air chamber 4; the air pump piston 5 is installed in the compressed air chamber 4; the connecting rod 10 is located in the air pump crankcase 97; when the air pump piston 5 in the compressed air chamber 4 continuously compresses air, it releases a large amount of heat, which is transferred to the oil chamber 1 through the housing 6, heating the heavy oil in the oil chamber 1 and playing the role of preheating the heavy oil; at the same time, the heavy oil in the oil chamber 1 also helps to dissipate heat from the air pump piston 5 and other compressed air parts in the compressed air chamber 4.

[0029] 2. Oil chamber overflow pressure stabilization principle: Heavy oil is drawn from the tank by the oil pump, pressed into the oil chamber 1 through the oil inlet 13, and then flows into the injection system through the oil outlet 12. However, when the pressure in the oil chamber 1 is too high, it can overcome the sum of the pressure of the first spring 71 and the deformation critical force of the flexible valve plate 3 itself, causing the flexible valve plate 3 to bend towards the side of the air chamber 2. This causes the flexible valve plate 71 to separate from the side of the back pressure port 11 and the return port 15, allowing the back pressure port 11 and the return port 15 to communicate with each other. The heavy oil will be discharged back into the oil tank through the return port 15. When the oil pressure in the oil chamber 1 drops to a certain pressure value, the flexible valve plate 3 returns to its original shape and closes tightly to the back pressure port 21 and the return port 15 again to seal them, thereby stabilizing the heavy oil pressure in the oil chamber.

[0030] 3. Air chamber overflow pressure stabilization principle: Inside the compressed air chamber 4, the air pump piston 5 reciprocates, continuously drawing gas into the compressed air chamber 4. Then, the gas passes through the gas one-way valve and enters the air chamber 2 from the air chamber inlet 22, and then enters the fuel injector through the air passage 24 to assist in atomization and fuel injection. When the air pressure in the air chamber 2 exceeds the set pressure value in the pressure relief valve, the pressure relief valve opens, and the excess gas in the air chamber 2 is discharged through the pressure relief air passage 23, thereby ensuring that the air pressure in the air chamber 2 remains stable within a certain pressure value.

[0031] 4. Back pressure stabilization principle: By controlling the elastic force of the first spring 71, the oil pressure limit value in the oil chamber 1 can be changed; by changing the opening pressure of the pressure relief valve, the pressure value in the air chamber 2 can be limited; and when the valve plate 8 in the gas check valve slides up and down, the lubricating oil in the annular oil groove 44 can stick in the gap between the outer circle of the valve plate 8 and the air inlet 22, thereby increasing the resistance of gas passage through the gas check valve, thus preventing the gas in the air chamber 2 from flowing back into the compressed air chamber 4 when the air pump piston 5 falls back, making the gas pressure value in the air chamber 2 more accurately limited; according to the required back pressure value between air pressure and oil pressure, the specifications of the first spring 71 and the pressure relief valve are selected, thereby accurately controlling the back pressure between air pressure and oil pressure.

[0032] In summary, this invention integrates the compressed air chamber, air chamber, and oil chamber into a compact structure, enabling the direct preheating of heavy oil in the oil chamber using the heat generated by compressed air. The absorption of heat by the heavy oil also facilitates heat dissipation of the working parts within the compressed air chamber. By precisely limiting the critical value of the deformation force of the flexible valve plate, the through pressure value of the pressure relief valve, and the design of the gas check valve, not only can the oil pressure and air pressure be precisely regulated separately, but the stability of the back pressure value is also ensured.

[0033] The foregoing description of specific exemplary embodiments of the invention is for illustrative and explanatory purposes. These descriptions are not intended to limit the invention to the precise forms disclosed, and it will be apparent that many changes and variations can be made in accordance with the foregoing teachings. The exemplary embodiments were chosen and described in order to explain the specific principles of the invention and its practical application, thereby enabling those skilled in the art to implement and utilize various different exemplary embodiments of the invention, as well as various different choices and variations. The scope of the invention is intended to be defined by the claims and their equivalents.

Claims

1. A ignition-type direct injection heavy oil engine air pump integrated overflow pressure regulating valve, characterized in that, include: Oil cavity (1), which is provided with back pressure oil port (11); The air chamber (2) is provided with a back pressure air port (21) and an air chamber inlet (22). The back pressure air port (21) is connected to the back pressure oil port (11), and the air chamber (2) is connected to the pressure relief air passage (23). The oil return channel (14) is located on one side of the oil chamber (1), and the oil return port (15) at one end of the oil return channel (14) is connected to the back pressure port (21). The flexible valve plate (3) seals the back pressure oil port (11) and the return oil port (15) on one side, and seals the back pressure air port (21) on the other side of the flexible valve plate (3). A compressed air chamber (4) is provided with an air outlet (41) connected to the air inlet (22) of the air chamber, and a gas check valve is provided between the air outlet (41) and the air inlet (22) of the air chamber. An air pump piston (5) is disposed in the compressed air chamber (4) and is capable of compressing the air in the compressed air chamber (4); A pressure relief valve, which is connected to the pressure relief air passage (23); as well as The housing (6), the oil chamber (1), the air chamber (2) and the compressed air chamber (3) are all located in the housing (6).

2. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, It also includes a pneumatic valve seat (25) located in the air chamber (2), the pneumatic valve seat (25) having a plurality of pneumatic valve holes (26), and a first spring (71) located on the pneumatic valve seat (25), the first spring (71) pressing the valve core (7) against the other side of the flexible valve plate (3).

3. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, The oil chamber (1) is also connected to the oil outlet (12) and the oil inlet (13).

4. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, The air chamber (2) is also connected to the air outlet (24).

5. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, The compressed air chamber (4) is also provided with an air inlet (42).

6. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, The air outlet (41) is connected to the air inlet (22) of the air chamber, and an annular limiting surface (43) is provided between the air outlet (41) and the air inlet (22) of the air chamber. An annular oil groove (44) surrounding the air outlet (41) is provided on the annular limiting surface (43).

7. The integrated overflow pressure regulating valve for an ignition-type direct injection heavy oil engine air pump according to claim 6, characterized in that, The gas check valve includes: A valve plate (8) is slidably disposed within the air chamber (2), and the diameter of the valve plate (8) is adapted to the diameter of the air inlet (22) of the air chamber; and The second spring (81) is located on one side of the valve plate (8) so that the valve plate (8) fits tightly against the annular limiting surface (43).

8. The integrated overflow pressure regulating valve for the air pump of the spark-ignition direct injection heavy oil engine according to claim 1, characterized in that, The pressure relief valve includes: A valve chamber (9) is located in the housing (6). One end of the valve chamber (9) is connected to the pressure relief passage (23), and the other end of the valve chamber (9) is connected to the vent (96). A pressure relief valve seat (91) is provided at one end of the valve cavity (9), and a pressure relief valve hole (92) is provided in the pressure relief valve seat (91). A valve core (93) is slidably disposed within the valve cavity (9). One end of the valve core (93) contacts the pressure relief valve seat (91) via a steel ball (94) and is capable of sealing the pressure relief valve orifice (92). A third spring (95) is located between the valve core (93) and the other end of the valve cavity (9).

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